The benefits are set to expire at the end of the year, and McConnell said he is working with House Speaker Paul Ryan to include money for the miners in a short-term spending bill slated for a vote this week.

But Democrats said the GOP solution only lasts for a few months and does not protect pension benefits that also are at risk. McConnell's proposal would pay for miners' health care for the next four months by seizing money from their current health-care plan, Democrats said.

"The Republican leader is turning his back on American coal miners," said Sen. Sherrod Brown, D-Ohio.

Brown and other Democrats said they will push for a bipartisan bill that would protect retirement and health-care benefits for about 120,000 retired coal miners and their families.

Republicans have blocked a vote on the bill on the Senate floor. McConnell and other GOP leaders are wary of bailing out unionized workers, with some arguing that all coal miners should get the help.

Some Republicans also say the bill could pressure Congress to offer similar help to other cash-strapped pension funds. Their opposition was criticized by Brown and other Democrats.

"We had the chance to protect the retirement and health care coal miners have earned and save taxpayers money in the process, but Washington leaders chose to pull a bait and switch instead," Brown said. "This is everything that's wrong with Washington."

Sen. Joe Manchin, D-W.Va., said he would block other bills on the Senate floor until miners get their full health care and pension money — about $3 billion over the next 10 years. Manchin warned colleagues they may have to stay through Christmas unless the issue is resolved.

In a speech on the Senate floor, Manchin said retired miners deserve benefits that are now at risk amid the coal industry's steep decline and bankruptcies of several large mining companies. Without congressional intervention, some of the funds could run out of cash by next year, according to the United Mine Workers of America.

"We are the country that we are because of the hard work that they've done," Manchin said, referring to miners in his state and across Appalachia.

"If we don't stand for the people that have made our country as great as it is, we stand for nothing," Manchin said.

McConnell said his plan would protect benefits for miners suffering from what he called the Obama administration's "war on coal," combined with "challenges within the energy market (that) have led to a dramatic increase in bankruptcies and lost coal jobs, exhausting the health benefits of thousands of coal workers and retirees."

While he recognizes the plan "will not solve the challenges of every coal miner or retiree in Kentucky, this provision will help address many of the health care needs of thousands of miners who fell victim to the steep downturn in coal production," McConnell said.